Various fluid-operated wrenches, including drive means in form of a cylinder and a piston reciprocating therein which drive over a ratchet arrangement a shaft to which a socket is connected for engaging a threaded connector to tighten or loosen the same, are known in the art. One drawback of these known construction is, that when the wrench has to be used for loosening instead of tightening a threaded connector, the whole wrench has to be turned around through 180.degree. which makes for a cumbersome operation.
Since during driving of the ratchet and the socket connected thereto in one direction, a force is created tending to turn the whole wrench in the opposite direction, most of the fluid operated wrenches include also a reaction member, for instance adapted to abut against a threaded connector adjacent to the one to be turned, to counteract this force. If the threaded connector has to be turned in tightening direction, this reaction member has to abut against one side of the adjacent threaded connector and if the wrench is used for loosening a threaded connector the reaction member has to abut against the other side of the adjacent connector. But this is not possible in all cases, since sometimes if two flanged tube members have to be connected by the threaded connectors, the threaded connectors are so close to the outside surface of the tubes so that the reaction member cannot be placed between the adjacent threaded connector and the projecting tube.
Another drawback of known fluid operated wrenches is that the overall height of the wrench is rather large so that its application in certain constructions is extremely difficult and sometimes even impossible.